The present invention relates to devices for introduction into a body via a substantially straight conduit to form a predefined curved configuration, and methods employing such devices.
It is known to insert straight elements into various types of bodies. In the general field of mechanical engineering, this includes insertion of drills, nails, screws and rods of various kinds into structures such as walls, articles such as furnishings, other inanimate bodies, plant bodies such as wood, and animal or human bodies. In certain cases, the straight elements have structures or mechanisms for securing the elements against withdrawal from the body.
It is also known in certain contexts to insert elements with a fixed degree of curvature into a body. Examples of this kind include curved needles such as are used for sewing leather, and arcuate drills for medical applications, such as described in U.S. Pat. No. 4,312,337 to Donohue and U.S. Pat. No. 4,941,466 to Romano. Such structures are limited to a very superficial depth of penetration into the body, and generally channel through an arc of less than 180° within the body.
In a third group of applications, primarily limited to the field of medical endoscopy, steerable flexible elements are introduced into a body. Steerable flexible elements can be introduced through straight conduits and can then be deflected within the body in order to steer them to a desired location, thereby allowing the elements to reach a location at an arbitrary desired depth within a body. These elements, however, do not generally assume a well defined curved configuration within the body, and typically do not turn through angles of more than about 180°. In many cases, steerable elements are specifically kept away from their mechanical limit of flexing in order to avoid structural damage through over-flexing.
None of the above provide a structure or method through which a curved structure can be introduced into a body via a straight conduit and then assumes a deployed position in a predefined curved configuration within the body, and particularly where the predefined curved structure turns through more than 180°, has a variable curvature and/or assumes a three dimensional (non-planar) geometry.
There is therefore a need for devices for introduction into a body via a substantially straight conduit to form a predefined curved configuration, and methods employing such devices.